Gang lawn mower with self-sharpening means

ABSTRACT

A gang lawn mowing machine having a tractor with a prime mover and ground supporting wheels. A plurality of mowers are supported on the tractor and are driven by the tractor in the cutting action of the mowers so that the mowers are powered. Pivot mountings support the mowers on the tractor for articulation of the mowers to adjust to irregular ground and for raising the mowers to a transport position compact with the tractor. A mower cutter drive train extends between the tractor prime mover and each of the mowers for rotating the mower cutter in a mowing direction of rotation. A reversing drive exists between the prime mover and the mowers for reversing the direction of rotation of the mower cutters and thereby sharpening the cutters when they are rotated in the reverse direction.

[451 June 13, 1972 [54] GANG LAWN MOWER WITH SELF- SHARPENING MEANS [72] Inventors: Sahag C. Akgulian; Donald G. Haflner;

Sherman C. Beth, all of Racine, Wis.

3,410.063 ll/l968 3,472,005 lO/l969 Speiser ..56/7 Profenna ..56/7

Primary Examiner-Russell R. Kinsey Anorney-Arthur J i Hansmann 57] ABSTRACT A gang lawn mowing machine having a tractor with a prime mover and ground supporting wheels. A plurality of mowers are supported on the tractor and are driven by the tractor in the cutting action of the mowers so that the mowers are powered. Pivot mountings support the mowers on the tractor for articulation of the mowers to adjust to irregular ground and for raising the mowers to a transport position compact with the tractor. A mower cutter drive train extends between the tractor prime mover and each of the mowers for rotating the mower cutter in a mowing direction of rotation. A reversing drive exists between the prime mover and the mowers for reversing the direction of rotation of the mower cutters and thereby sharpening the cutters when they are rotated in the reverse direction.

7 Claims, 13 Drawing Figures PATENTEDJUH 13 Ian SHEEI 10F 7 8 INVENTORS RMAN .HETH

ORA/E PATENTEDJUH 13 1912 SHEET 3 0F 7 I N I/EN TORS SAHA G C. AKGUL l/W DONALD G. HAP/WEE Sl-IERMAN C. HE TH fro/WE) PATENTEmuma m2 3.668.844 SHEET 5 OF T I Nl/E N TORS SAHAG C. AKGbL/A/V DOMILD G. HAFFNER SHERMAN C. HE TH J /1 TTORNE) PATENTEHJux I 3 19:2 3. 668 .844

sum 7 or 7 INVENTORS: 541 -1446 C. A/(GUL/AN DOM4LD G. HAFWER WERAMN HETH ATTORNEY GANG LAWN MOWER WITH SELF-SHARPENING MEANS This invention relates to a gang lawn mower with self-sharpening means. More particularly, it relates to a gang lawn mower of the type having a tractor and a plurality of powered mowers, and with powered means for sharpening the mower cutters.

BACKGROUND OF THE INVENTION In considering reel type lawn mowers which commonly operate against a stationary bed knife as the reels are rotated across the bed knife, it is commonly known that the cutting edges on the reel and the cutting edges on the bed knife become dull through wear and damage by foreign debris getting on the cutting edges. That is, rocks, sticks, and the like positioned between the rotating reel and the bed knife will cause the cutting edges to be nicked and dulled. Also, simply common and ordinary use of the powered reel mower will eventually cause the mower cutting edges to become dull. It is also common knowledge that the cutting edges can be sharpened by reversing the direction of rotation of the reel across the bed knife, so that the reel is rotating in a non-cutting direction but the cutting surface angle is such that the cutting edge on both the reel and the bed knife come into contact and are therefore sharpened during the reverse rotation. A substance may be applied between the two edges so that during reverse rotation the substance will cause the original cutting angles to be re-established so that the edges are again sharp. Such reverse rotation is akin to a lapping process.

The problem with sharpening reel type mowers is that the mower must be individually handled and operated in the reverse direction for the sharpening procedure described above. This means that in a gang type lawn mower, each of the mowers must be removed from the machine or tractor, and the mower is commonly taken to a shop for the sharpening process.

The present invention provides means for sharpening the mowers without requiring that they be removed from the machine or tractor. In accomplishing this object, the means employed is also arranged so that it utilizes the prime mover and the drive mechanism of the machine itself. That is, the tractor engine or prime mover which is commonly used to drive the mowers in their cutting action is also used to drive the mowers in the reverse direction for the sharpening process.

Another object of this invention is to provide the means for sharpening the mowers and to do so in a simple and expedient structure and manner so that one can easily and readily carry out the sharpening process and do so with a minimum of time and effort.

Still another object of this invention is to accomplish the aforementioned objects and to do so with a reverse drive means for use in sharpening the mowers and with the reverse drive means being arranged so that one cannot inadvertently utilize the reverse drive means.

Still another object of this invention is to provide a mower drive means which can be readily and easily adjusted to assure optimum cutting efficiency of the mower reel against the bed knife, and which can also be similarly adjusted for the lapping process employed during sharpening of the mowers. In accomplishing this object, all of the mowers are of the powered type and therefore have a positive drive extending to the mower reels, but, at the same time, the reels are adjustable relative to the bed knife so that the optimum cutting efficiency can be achieved and the mower sharpening operation can be carried out after the reels have been adjusted to the optimum position for the sharpening process.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a gang lawn mower having a preferred embodiment of this invention.

FIG. 2 is a front elevational view of FIG. I, but with the mowers in the raised and transport position.

FIG. 3 is a top plan view of a central portion of FIG. I.

FIG. 4 is an enlarged rear elevational view of a portion of FIG. 1.

FIG. 5 is a sectional view taken on the line 5-5 of FIG. 4, and with parts added thereto.

FIG. 6 is a front perspective view of a portion of FIG. I, on an enlarged scale.

FIG. 7 is a side perspective view of a portion of FIG. I, on an enlarged scale.

FIG. 8 is a sectional view taken on the line 8-8 of FIG. 6.

FIG. 9 is a sectional view similar to FIG. 8, but showing a different mower.

FIG. 10 is an enlarged perspective view of a fragment of FIG. I, and with the view being taken from the front right side of the machine of FIG. I.

FIG. 11 is a rear perspective view of FIG. II), with parts added thereto and with parts removed, and with the parts shown in their raised or transport position.

FIG. 12 is an enlarged side elevational view of a fragment of the mower shown in FIG. I.

FIG. I3 is a bottom plan view of FIG. I2, on a reduced scale and showing a fragment thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A tractor frame I0 supports an engine I1, an operators seat 12 and a steering wheel 13. Two rearwardly mounted ground wheels 14 and two forwardly mounted ground wheels 16 are also included in the tractor. The rear wheels 14 are the steering wheels which are controlled by steering arms 17 suitably connected to a steering rod 18 extending between the upright rear wheel connector 19 and the steering column 21. The front wheels 16 are the powered or traction wheels, and they are shown to be driven through a hydraulic unit designated 22 which is powered through a rod 23 extending between the unit 22 and a box 24. The engine 11 has a shaft 26 extending to the box 24, and a suitable sprocket and chain drive extends in the box 24 from shaft 26 and connects to the rod 23 for powering the hydraulic unit 22 which in turn drives the front traction wheels 16.

Five reel type lawn mowers are powered by the prime mover II and are pivotally supported on the tractor or its frame 10, and such mowers are the two front mowers 27 and 28 and the two side or wing mowers 29 and 30 and the center mower 31, all five ofwhich are shown in FIGS. 2 and 3.

The front mowers 27 and 28 have a sleeve 32 which telescopically receives a shaft 33 attached to a pivot arm 34 pivotally mounted on a pin 36 on the tractor frame 10. A tension spring 37 is connected to the arm 34 and the tractor I0 and is therefore available for transferring some of the weight of the front mower to the tractor, and there is a spring 37 for each of the two front mowers 27 and 28. Also, arm 34 has a pin 38 which swings into the path of the position of a latch 39 on the tractor 10, and the pin end 41 is engaged by the latch 39 to hold the front mower in the raised position of FIG. 2. FIG. 6 shows the front view of the latch 39, and the operator would simply grip the forwardly projecting end of the pin 38 and lift the front mower into the latched position described.

Wing mowers 29 and 31 are pivotally supported on the tractor 10 through a support arm 42, rigid with the tractor frame 10 for providing a pivot shaft 43 for each respective one of the wing mowers 29 and 30. Thus, a pivot arm 44 is piloted on the shaft 43 and carries a shaft 46 which is telescoped in a sleeve 47 secured to the wing mower.

The center mower 31 is also pivoted on the tractor l0, and it has a shaft 43 supported on the frame arm 42 and telescopically received within a sleeve 49. A mower pivot arm 5! extends from a connection with the sleeve 49 and to a shaft 52 telescopically received within a sleeve 53 affixed to the mower 31.

FIGS. 2, l0, and II show that the wing mowers 29 and 30 and the center mower 31 are pivotal to the transport position and are connected together for raising the mowers. The operator can lift the wing mowers 29 and 30, and each mower has a tension spring 54 connected to the mower pivot arm 44, through a plate 56, and connected to the tractor 10, in any suitable manner. The wing mowers and center mower are connected through an adjustable linkage 57, the opposite ends of which are slidable in slots 58 on plates 59 mounted on each of the two wing mowers and on the center mower. FIG. 2 shows that when the wing mower 29 is raised, the linkage 57 forces upwardly on the bracket 59 on the center mower 31 to raise the center mower to the position shown in FIG. 2. A similar linkage 57 and two brackets 59 connect between the right wing mower 30 and the right side of the center mower 31 to lift the right side of the center mower also.

A tension spring 61 is connected between the tractor l and the center mower lift arm 51 for taking some of the weight of the center mower 31.

The structure of each of the five mowers is identical and includes the two side plates 62 and 63, as shown in FIG. 6. Mower frame tubes 64 and 66 are connected between the side plates 62 and 63, and the mower respective sleeves, such as the sleeve 32, are secured to the cross-tubes 64 and 66. Reels 67 are rotatably mounted between the side plates 62 and 63 in a manner described later. Each side plate of the mower has a skid-shoe 68 vertically adjustably secured to the plate by means of a pivot bolt 69 and a slot 71 in the shoe 68. Also, a skid assembly 72 is included in the mower and is pivotal thereon and has two rear skids 73 and an intermediate torque tube 74 secured to the rear skids 73. FIGS. 12 and 13 show the rear skids 73 are pivotal on the mower by means of an arm 76 affixed to the shoe 73 and held to the mower bed knife 77 through a bracket 78. Thus the arm or rod 76 is pivotal in the bracket 78 for moving the rear skids 73 up and down and thereby adjusting the elevation of the mower, along with the adjustment of the skidshoe 68. To position the skid 76, an adjustable connector 79 extends between the mower tube 64 and the torque tube 74. The connector 79 consists of two telescoping sleeves 81 and 82. Outer sleeve 81 is connected to the torque tube 74 through a pin 83 and cars 84 which are affixed to the tube 74. Also, sleeve 81 is connected to the mower tube 64 through cars 86 on the tube 64 and an angled pin 87 which is threaded into the inner sleeve 82. Sleeves 81 and 82 both have a series of holes, namely, 88 and 89, respectively, and these holes can be matched in aligned pairs for receiving a locking pin 91, as shown in FIG. 7. With the four holes 88 in sleeve 81 and the three holes 89 in sleeve 82, there are l2 different pin positions possible for setting the elevation of the skids 73. Further, the angle pin 87 is threaded at 90 and into inner sleeve 82 so that an additional adjustment in elevation is possible by virtue of the threaded arrangement described.

It will therefore be seen that each mower has a bed knife 77 for presenting a cutting edge 93 on the angled surface 94 which is presented to the reel 67. The knife 77 is secured to the mower side plates 62 and 63, but the reel 67 can move toward and away from the knife 77, for the desired adjustment. Thus, the side skid 68, and the rear skid assembly with shoes 73, support the mowers on the ground such that the rear skids 73 normally hold the mowers in the mowing position, and the side skids 68 are available for further upwardly supporting the mowers if they meet a rise in the ground. Also, the tube 74 extending across the width of each mower is available for suspending an end of the mower over a rise in the ground or a curb or the like, and the tube 74 would then function as a torque tube to transfer the support from the shoe 73 which is on the ground and to the opposite side of the mower. Therefore, FIG. 12 shows the skid-shoe adjustment with the tube 74 in the maximum upward position and therefore it would be understood that the lowest holes 88 and 89 are aligned and secured by pin 91, as indicated in FIG. 7. Further, plate 86 has a hole 96 which can also receive the upper end of the angle shaft 87, so a further elevational adjustment is available. With this arrangement, all mowers can be readily but very accurately placed in the same mowing elevation. The reels have cutting edges 95 which are sharpened.

Particularly FIGS. 6 through 9 show the mower construction with the arrangement and the mounting of the reel 67 having the usual plurality of cutting blades 97, shaft 98 and support plates 99, all rotatably mounted for cutting rotation. Thus, end plates 62 and 63 have large openings 101 which provide for the passage of the opposite ends of reel shah 98 and which accommodate reel bearings 102. A gear box 103 is shown on the plate 62 in FIGS. 6 and 8 which show the front mower 27. Bevel gears 104 are at right angle relation in the box 103, for driving the reel 67 from a drive train described later. A bearing support member 106 is suitably supported on mower side plate 63 for supporting the adjacent end of the reel shaft 98.

FIG. 7 shows the right front mower 28, and it shows the bearing support member 106 which is pivoted to the outer side plate 62 at the mounting bolt 107. A bolt 108 connects the forward end of the member 106 with an upright adjusting screw 109 which is anchored on the plate 62 by a fixed bracket or plate 111. Upper and lower adjusting nuts 112 connect the screw 109 with the plate 111 to set the vertical position of the screw 109 and therefore the vertical position of the connecting stud 108 with the member 106. Also, the nuts 112 are shown to have conically shaped inner ends 113, so they fit tightly in the conically upper and lower pockets on the plate 111 which snugly receives the conical portions 113 of the nuts 112, regardless of the angle of the extension of the screw 109 through the plate 111, according to the adjustment for the member 106. Further, mower side plate 62 has adjusting slots 114 which accommodate the mounting bolts 116 extending through the member 106 and through the slots 1 14 of the side plate 62. With the arrangement described, bolts 107 and 116 and stud 108 can be loosened, and nuts 112 can be loosened and adjusting screw 109 can be moved up and down by repositioning the nuts 112 on the screw 109. This of course adjusts the vertical position of the reel shaft 98 at its end adjacent the mounting member 106, so the reel blades 97 are adjusted relative to the bed knife edge 93.

FIG. 6 shows that the gear box 103 is also vertically adjustable, just as described in connection with the mounting member 106, and again the adjusting screw 109 is secured on the plate 111 on mower side plate 62, and the box 103 has a boss 117 which connects with the lower end of the screw 109, and the box 103 also has a boss 118 which receives a mounting bolt extending through the plate 62, just as the bolts 116 extend through the mounting member 106. Further, the box 103 has a pivot bolt similar to the bolt 107, so, as clearly indicated and described, the box 103 is also vertically adjustable, just as the mounting member 106 is vertically adjustable. Further, both adjusting screws 109 have the conically shaped nuts 112 which are ultimately tightened against the plates 111 and into the conically shaped pockets in the plates 111, so that the nuts 112 are snug with the plates 111 and therefore the adjusting screw 109 is securely fixed for the critical and accurate adjustment desired, and this arrangement of conical nuts 112 exists on both ends of the mower. Therefore, both ends of reel shaft 98 are vertically adjustable relative to the bed knife 77, and such adjustment exists on all live mowers.

FIG. 8 shows mower 27 has a compression spring 119 applied between the bearing 102 and a washer 121 affixed to the end of the reel shaft 98. Thus the spring 119 urges the reel 67 to the right, as viewed in FIG. 8, and this is the direction which the normal and conventional spiral of reel blades 97 would also urge the reel 67 in the function of mowing. Then, if the reel 67 hit debris, the spring 119 would permit the reel blade 97 to accommodate the hitting of the debris as the reel 67 moves to the left, as viewed in FIG. 8, against the pressure of spring 119. This of course means that the gear 104 on shaft 98 would slightly adjust its position relative to the other gear 104, but the reel blades 97 would be protected from damage of hitting the debris.

FIG. 9 shows the center mower 31 with its reel 67 and blades 97, and this mower has a shaft 122 extending through mounting members 123 and bearings 124, as shown. In this center mower, a compression spring 126 acts against the shaft shoulder 127 and the bearing 124 to again urge the reel 67 in the same direction that the spiraled blades 97 of the reel 67 are urged in the normal course of mowing and in the normal action of the blades 97 against the bed knife 77, as is commonly known. However, when the blades 97 hit debris, then the spring 126 permits the blades 97 to become somewhat released relative to their movement toward the bed knife 77 and toward the debris thereon, so again the reel 67 is protected from damage.

FIG. 10 shows the right-hand end of center mower 31, and it shows mower plate 62 and mounting member 123 with the upper adjusting slot 114 which accommodates the mounting bolt 116. The pivot bolt 107 is also shown, all as described in connection with FIG. 7 and mower 28 relative to the vertical adjustment of the reels 67 to their respective bed knives 77. Of course the other mounting member 123 on center mower plate 63 is also vertically adjustable, as shown in connection with the one shown plate 123 in FIG. 10. It will also be understood that the wing mowers 29 and 30 have adjusting mounting members 123, and FIG. 10 shows the adjusting slots 114 for accommodating the mounting member 123 on the plate 63 of the wing mower 30. The mounting member 123 would also be on the plate 62 of the wing mower 30, and the same arrangement would be provided on the wing mower 29.

FIGS. 10 and 11 further show the mounting of the wing mower, the pivot thereof, and the connection between the center mower 31 and the wing mower 30, which connection is similar to the connection between the center mower 31 and the wing mower 29. Thus FIG. 10 shows the mowers down in the mowing position, and it will be seen that the linkage 57 has an adjusting screw 128 for adjusting the length of the linkage 57 and thereby adjusting the connection between the center mower and the wing mowers. Also, the linkage pin 129 is shown slidable in the bracket slot 58, and the other end of the linkage 57 would likewise be slidable in the slot 58 of the bracket 59 on the wing mower.

When the wing mower is lifted manually, the spring 54 is available for assisting the lifting, and the mower tube 66 abuts an arm 129 on the pivot arm 44. This abutment keeps the wing mower in the desired attitude as it is being raised, so the mower on its plate end 63 cannot swing upwardly beyond the arm 129. Also, because oflinkage 57, the mower plate 63 cannot swing excessively away from the arm 129, with both swing directions being relative to the mounting sleeve 47. Thus, the arm 44 is pivoted to the upright position of FIG. 11, which is the transport position also shown in FIG. 2. When the wing mower is in the position of having its reel axis vertical, the mower plate 63 is then in abutment with a projection 131 on tractor frame 10, as shown in FIG. 11. Here again, link 57 prevents the wing mower from overtipping about the sleeve 47, and the wing mower is therefore held in a secured position by means of the link 57 and the tractor frame abutment piece 131. In the raised position, a latch 132, pivotally mounted on the pin 133 on arm 44 engages a pin 134 on tractor frame 10, to hold the wing mower in the transport position by virtue of holding the arm 44 on its pivot shaft 43.

In the FIG. 2 and FIG. 11 position, the linkage 57 has pulled upwardly on its respective connected end with the center mower 31, so the center mower is then also in the raised or transport position, as shown in FIGS. 2 and 11. The center mower raising was also assisted by the heretofore described spring 61 connected between the tractor I and the arm 51 which mounts the center mower 31.

FIGS. 1 through show the drive train for powering the five mowers. A drive shaft 136 is driven by the engine 11, in a manner described later, and it extends to a forward location on the tractor where the shaft 136 is suitably rotatably supported on the tractor l0 and carries a sprocket 137. A drive chain 138 is on the sprocket 137 and is connected to a lower sprocket 139 which may be on a universal joint shaft 141 suitably rotatably mounted on a plate 140 on the frame 10. Universal joint shaft 141 connects to a forwardly extending universal joint shaft 142 which terminates in a universal joint connection 143 connected to a shaft 144 extending into gear box 103 for driving the front mower 27. Also, a right-angle gear box 146 is suitably supported on the frame 10 and contains bevel gears 147 which drive shaft 148 extending over to bevel gears 149. Gears 149 in turn drive a universal joint shaft 151 connected through a universal joint 152 to a shaft 153 extending forwardly to a universal joint 154 which drivingly connects with gear box 103 of front mower 28. With this sprocket and universal joint drive described, the front mowers 27 and 28 are powered and are driven at the same and controlled speed. Also, with the universal joints extending in pairs to each of the front mowers 27 and 28, the drive train described permits the pivotal action of the mowers, both during mowing and when raising the mowers 27 and 28 to the transport position shown in FIG. 2.

FIG. 1 shows that the shaft 141 is located so that the mower 27 can swing up and down about a substantially central pivot point as determined by the vertical location of shaft 141. However, the shaft 142 is a spline type drive having two telescoping sections 156 and 157, to permit the necessary variation in the length of the shaft 142 from the rear universal joint thereon to the forward universal joint 143. It will also be noted that the mower mounting sleeve 32 is offset relative to the fore-and-aft axis of the front mowers 27 and 28, respectively, so that the sleeve 32 is toward the gear box 103 on each respective mower. Therefore, in the mowing function and in the transport position shown in FIG. 2, the mowers 27 and 28 will be over-balanced so that they abut the stop pin 38, as shown and as desired. Further, the mowers 27 and 28 should not swing about the sleeve 32, in a direction to have their respective gear boxes 103 move downwardly in FIG. 2. This assures that the spline drive shafts 142 and 153 will not come apart. Still further, the spline drives or shafts 142 and 153 are actually limited in their outer lateral movement, in the event the mowers were to swing as just described, and such limit is because the splined shafts 142 and 153 would abut the tractor front wheels 16, if the mowers 27 and 28 were to swing to that extent and about their respective sleeves 32.

Continuing to trace the drive train to the mowers, the two wing mowers, and the center mower are driven by the drive shaft 136 through a sprocket 158 which drives a lower sprocket 159 through a chain 161. Universal joint 162 is driven by sprocket I59 and a first spline shaft 163 slidably telescopically connects to a second spline shaft 164 which, through a universal joint 166 and a shaft 167, extends into a gear box 168 mounted on one end of the center mower 31. Two bevel gears 169 are thus driven in the box 168 and they drive a sprocket 171 which drives a sprocket 172 through the chain 173, so that a shaft 174 is rotatably driven. The shaft 174 is suitably rotatably mounted on the center mower 31, in a manner similar to that shown and explained with regard to a shaft 176 on the right end ofmower 31 and shown in FIG. 10.

Universal joint shafts 174 and 176 are conventionally and appropriately connected to opposite ends of the center mower reel shaft 122, so that all rotate together. FIGS. 3, 10, and 11 then show that universal joint shaft 176 has a universal joint 177 connected to a first spline shaft 178 which in turn is telescopically splined with a second spline shaft 179. Shaft 179 has a connection to a universal joint 181 which in turn has a shaft 183 which is suitably connected to the mower reel shaft of the center mower, and which may be shown as shaft 183 in FIG. 10. Similarly, universal joint shaft 174 connects to a universal joint 184 which in turn connects to a first spline shaft 186 extending toward the wing mower 29 and being drivingly connected to the reel 67 of the wing mower 29, in the manner described in connection with wing mower 30 as seen in FIG. 10.

With the drive described, all of the live mowers are driven at a controlled and identical speed. Further, it will be seen in FIG. 3 that the center mower support or mounting sleeve 53 is offset toward the left, as viewed in FIG. 3, relative to the longitudinal axis of the center mower 31. Such offset provides the necessary balancing of the mower 31, weightwise, because of the extra weight exerted downwardly on the mower 31 and by the gear box 168 and the connections thereto as described. Still further, as seen in FIGS. 2, 10, and 1 1, the linkage 57 connects between the respective ends of the center mower 31 and the respective wing mowers 29 and 30 to lift the center mower 31 and to prevent the slidable telescoping splined shafts 178 and 179 from pulling away or apart relative to each other. This is true both during mowing, when the wing mower end plate 63 may be swung away from center mower 31, either during mowing, or in the raised transport position.

Also, the drive to the wing mowers 29 and 30, and the pivot for them, by pivot arms 44, are arranged so that the resistance of the mowers against the ground would tend to pivot the arms 44 rearwardly of the tractor 10. Taking this into consideration, the spring 54 is then disposed to also urge the arm 44 rearwardly, so there is no play or clearance, at least during mowing, relative to the horizontal positioning of the wing mowers 29 and 30.

With regard to the sharpening action of the mowers, FIGS. 1, 4, and 5, particularly show the drive to the mowers for reversing rotation of the mower reels 67 so that the lapping action can be performed in the sharpening function, as the reel blades 97 rotate in reverse against the bed knife surface 94. FIG. 1 shows the engine shaft 26 and a cover plate 187 over the end of the sprocket housing 24. Also, a stub shah I88 extends rearwardly from a clutch housing 189 suitably mounted on the tractor. FIG. shows a pressure type clutch 190 which is slidably splined on the tractor drive shaft 23. Shaft 23 has sprocket I91 driven by chain 192 driven by sprocket 193 on engine shaft 26. A clutch control arm 194 is suitably pivotally mounted on a shaft 196 on housing 189, and it controls the axial position of the clutch member 197 relative to the clutch plate 198 affixed to the shaft 23 for rotation thereof. Thus separation of the clutch members 197 and 198 will interrupt the drive to the stub or jack shaft 199 which carries the clutch member 197 and which is rotatable relative to the shaft 23. A gear 201 is affixed to shaft 199 to rotate therewith and to drive a gear 202 which is affixed to a stub shaft 188, rotatably mounted and supported by the housing 189, and a support cover 204 which is removably attached to the housing 189. A gear 206 is affixed to shaft 188 to rotate therewith and to drive a gear 207 rotatably affixed to mower drive shaft 136. In this drive train, the engine 11 then drives the shaft 136 in one direction of rotation for rotating the mower reels 67 in the forward direction of rotation. Also, the clutch 190 is available for interrupting the drive to the mowers, and a clutch control 208 is located on the tractor for the purpose of controlling the clutch 190, as described.

FIG. 5 also shows a sprocket 209 mounted on the stub shaft 188 for rotation therewith, and a chain 211 is on the sprocket 209 and extends up to a sprocket 212 which is on a shaft 213 rotatably supported in a bearing 214 held by arms 216 removably mounted on the housing 189 and housing cover 204. Shaft 213 connects to the engine shaft 26, when the cover 187 is removed from its FIG. 1 position, so shafts 26 and 213 rotate together to drive the sprockets engaged with the chain 211. At the time that the sprockets 209 and 212, along with shaft 213 and chain 211, are all mounted as shown in FIG. 5, then the clutch 190 would be dis-engaged so that the drive would go directly from the engine shaft 26 and to the stub shaft 188. This would then rotate the gears 202, 206, and 207 in a direction reverse from that heretofore mentioned, and therefore the drive shaft 136 would also rotate in the reverse direction. With the re verse direction of rotation of the drive shaft 136, the mower reels 67 are also rotated in the reverse direction for the lapping and self-sharpening action mentioned and desired.

Therefore, all of the mowers are positively driven in the forward mowing position, and they are also positively driven in the reverse direction when the lapping action is taking place. Further, all of the mowers are articularly mounted for adjusting to the ground, as the mowers rock or pivot about their respective mounting sleeves 32 and 47. Still furthei', the respective sleeves 32 and 47 are both affixed to cradle plates 217 spaced apart in the fore-and-att direction of the mowers and each plate being respectively secured to the mower crosstubes 64 and 66 so that the mowers are stable in the horizontal plane while at the same time they are articularly mounted, as mentioned.

The drive train to the mowers, as described and as shown in FIGS. 1, 4, and 5 particularly, provides a transmission operative between the engine and the mowers, and a reversing mechanism is provided in this drive train or transmission, for the sharpening or lapping of the mowers. Also, just as the reel springs are available for permitting displacement of the reels when they strike debris, the springs are available for controlling the position of the reel during the lapping process so that the reel blades will be snugly disposed in sliding contact with the bed knife surface as the reels are rotated in reverse direction. Of course it will also be understood, since it is conventional and common knowledge to one skilled in the art, that the rotation of shaft 23, while it may be constant in its drive of the hydraulic unit 22, there would be a control for governing the unit 22 and thereby governing the drive to the traction wheels 16.

In the spring-mounted reels, the bearings 102 and 124 are conical bearings having inner races 217' and 217", on reel shafts 98 and 122, and outer races 218, 218' affixed with the respective bearing housings 103 and 123. The reel springs 119 yieldingly urge the reels in the direction of spiral action, and in the direction of force between the bevel gears 104, which direction of force is along the reel shaft 98 and to the right, as viewed in FIG. 8, all to protect the mower and the gears 104.

What is claimed is:

l. A gang lawn mower comprising a tractor including a prime mover and ground traction wheels, a plurality of reel type lawn mowers having a rotatable reel and a stationary bed knife, a plurality of arms pivotally mounted on said tractor, a respective one of said mowers pivotally mounted on the extending end of each respective one of said arms for articulation of said mowers in mowing position on the grass and for lifting said mowers completely off the grass, drive means operatively connected between said prime mover and said traction wheels for driving the latter, a drive train operatively connected between said prime mover and said mowers for rotating said reel of each of said mowers in a direction of cutting, and said drive train including drive reversing mechanism for sharpening said mowers by rotating said reels in the direction reverse to said direction of cutting.

2. The gang lawn mower as claimed in claim 1, wherein drive means is operatively connected with said drive train, and a clutch disposed intermediate said drive means and said drive train for selective interruption of the drive to said lawn mowers.

3. The gang lawn mower as claimed in claim 2, wherein said drive means includes a gear train and a rotatable shaft disposed in an intermediate position of drive along said gear train, and said reversing mechanism including a driving member removably mounted on said shaft for transmitting drive to said gear train at the location of said shaft.

4. The gang lawn mower as claimed in claim 3, wherein said reversing mechanism includes two sprockets and a chain operatively connected between said prime mover and said shaft.

5. The gang lawn mower as claimed in claim I, wherein said bed knife is rigidly mounted in said mowers in a fixed position therein, and adjustment mountings included in said mowers for adjustably mounting said reels relative to said bed knives for movement of said reels toward and away from said bed knives.

6. The gang lawn mower as claimed in claim 1, including a spring operatively disposed relative to said reel for yieldingly urging said reel in a direction along the length of said bed knife.

being articulate in its connection to said mowers, for driving said reels while permitting full pivotal positioning of said mowers relative to said tractor and in accommodation of the elevation of the ground on which said skids are supported. 

1. A gang lawn mower comprising a tractor including a prime mover and ground traction wheels, a plurality of reel type lawn mowers having a rotatable reel and a stationary bed knife, a plurality of arms pivotally mounted on said tractor, a respective one of said mowers pivotally mounted on the extending end of each respective one of said arms for articulation of said mowers in mowing position on the grass and for lifting said mowers completely off the grass, drive means operatively connected between said prime mover and said traction wheels for driving the latter, a drive train operatively connected between said prime mover and said mowers for rotating said reel of each of said mowers in a direction of cutting, and said drive train including drive reversing mechanism for sharpening said mowers by rotating said reels in the direction reverse to said direction of cutting.
 2. The gang lawn mower as claimed in claim 1, wherein drive means is operatively connected with said drive train, and a clutch disposed intermediate said drive means and said drive train for selective interruption of the drive to said lawn mowers.
 3. The gang lawn mower as claimed in claim 2, wherein said drive means includes a gear train and a rotatable shaft disposed in an intermediate position of drive along said gear train, and said reversing mechanism including a driving member removably mounted on said shaft for transmitting drive to said gear train at the location of said shaft.
 4. The gang lawn mower as claimed in claim 3, wherein said reversing mechanism includes two sprockets and a chain operatively connected between said prime mover and said shaft.
 5. The gang lawn mower as claimed in claim 1, wherein said bed knife is rigidly mounted in said mowers in a fixed position therein, and adjustment mountings included in said mowers for adjustably mounting said reels relative to said bed knives for movement of said reels toward and away from said bed knives.
 6. The gang lawn mower as claimed in claim 1, including a spring operatively disposed relative to said reel for yieldingly urging said reel in a direction along the length of said bed knife.
 7. The gang lawn mower as claimed in claim 1, including skids attached to said mowers for slidably supporting said mower on the ground, and said drive train being operatively connected to all said mowers for rotation of said reels in proportion to the speed of said prime mover, and said drive train being articulate in its connection to said mowers, for driving said reels while permitting full pivotal positioning of said mowers relative to said tractor and in accommodation of the elevation of the ground on which said skids are supported. 